In current designs of electric machines, the housing predominantly has a multipart construction. In particular, two designs are used in this connection. First, there is a three-part design of the housing as in DE 1 765 059 U, and second, there is a two-part design as in EP 1 041 699 B1.
The three-part design is made up of a central cylindrical body, in which the stator of the electric machine is accommodated, and two bearing supports, which terminate the housing on both sides. The bearing supports accommodate a floating bearing or a fixed bearing. A disadvantage in this construction is a long tolerance chain between the two bearings, which results in a widening of the functional air gap between the rotor and the stator, or requires a very narrow tolerance field for manufacturing the three individual housing parts.
Two-part housings allow for a manufacture at a wider tolerance field while maintaining a constant air gap, but are limiting with respect to flexibility and the fulfillment of varying requirements because the housings must be adapted almost entirely; for example in the event of modifications of possible predefined interfaces such as coolant or high-voltage terminals. This is also the case in three-part housings.
Casting methods such as the lost-foam casting method described in DE 693 18 449 T2 are generally used for manufacturing electric machines and specifically for manufacturing the housings of electric machines.
An objective of the exemplary embodiments and/or exemplary methods of the present invention is to design the construction of a housing of an electrical machine manufactured in the lost-foam casting method in such a way that a maximum flexibility may be achieved with respect to the different specified interfaces using a single housing variant.